Darkness at the End of the TunnelBy: Gabriel Schoenfeld The Weekly Standard | Tuesday, June 24, 2008

Israel has
just carried out a major aerial exercise, putting a hundred or so F-15s and
F-16s into the skies over the eastern Mediterranean,
evidently a rehearsal for a strike against Iran's
nuclear facilities. The move follows the statement earlier this month by Shaul
Mofaz, Israel's
deputy prime minister, that an Israeli attack on Iran's
nuclear program is "unavoidable." Israel
almost certainly knows the location of some of the critical nodes in the
Iranian program that it must hit if it is to set the Iranian effort back by
several years. It also possesses the technology to assure that its bombs will
fall close to or on their targets. But would such a strike succeed?

We cannot know the answer, and neither can the Israelis. The question calls
attention to what might be called the ongoing Counterrevolution in Military
Affairs.

The Revolution in Military Affairs was based upon silicon, in particular the
computer chips that make for precision-guided weapons. In the 1980s, the United
States developed the technology to drop
munitions near enough to their targets to ensure a high chance of destruction.
In World War II, the circular error probable--the radius of a circle into which
a projectile will land at least 50 percent of the time--was more than half a
mile. Today, thanks to GPS systems and laser- and infrared-guiding devices, the
radius is less than two dozen feet. Almost any given target can be knocked out
by the use of just one or two conventional bombs.

In the face of the threat of such efficient destruction, Iran
has not stood still. Some of its countermeasures are themselves based upon
computerized systems, including highly effective Russian-made surface-to-air
missiles that Iran
is set to take delivery of this fall. But Iran
is also employing a far older means of warfare: deep burrowing.

Subterranean combat is familiar to all students of military affairs. During
the Civil War, soldiers with coal mining experience dug a 511-foot-long tunnel
some 50 feet beneath the Confederate lines at Petersburg,
Virginia. The terminus was filled with
8,000 pounds of gunpowder, and the blast killed between 250 and 350 Confederate
soldiers. (The operation ended in disaster, however, when the Union troops who
had rushed into the crater to follow up the attack were slaughtered by
Confederate troops firing downward from the rim in what was described as a
"turkey shoot.")

More typical, though, is defensive digging. In Berlin,
beneath an otherwise unremarkable Chinese restaurant, are the ruins of the most
notorious underground facility in history: the Führer bunker. Adolf Hitler held
court here in the last phase of World War II, and it was in the bunker that, on
April 30, 1945, together
with his new bride, he ingested cyanide. As an engineering feat, the Führer
bunker was not particularly impressive; Hitler's honeymoon grave was a mere 28
feet underground.

At the dawn of the nuclear age, the USSR
constructed a vast network of tunnels under Moscow,
including a 17-mile secret subway line to Vnukovo airport, to ensure that the
leaders of the Kremlin would survive a nuclear strike. Some of these
underground facilities were hundreds of yards deep and could accommodate
thousands of people, sustaining them in compartments impervious to chemical and
biological attack. It required a totalitarian system to marshal the manpower
and resources to remove such an immense quantity of soil and rock.

Today, however, tunneling is far cheaper and easier. In the
early 1990s, the Chunnel, the 30-mile rail tunnel connecting France
and England,
was built using drilling machines that hewed out a 30-foot diameter circle of
rock at the remarkable pace of 164 feet a day. Modern drills are huge,
multi-million-dollar pieces of machinery. They operate with a circular disk on
the front end that holds steel teeth, which cut into the rock as the plate
rotates. A conveyor system pulls the spoil backward, while workers follow up,
erecting a reinforced lining for the excavated structure. Narrower diameter
tunnels than the Chunnel can be carved into solid rock at the staggering rate
of 650 feet per day.

The military significance of all this cannot be overemphasized: Ultra-deep
shelters for critical military facilities can be made formidably resistant to
attack. It is exceedingly difficult to discern from the surface where tunnel
ventilation shafts are located or in which direction a tunnel proceeds. One has
only to consider the trouble Israel has had finding tunnels dug by Hamas out of
the Gaza Strip that are just a couple of yards below the surface. Another
difficulty is determining exactly what military activities are being conducted
in any given tunnel.

What is more, if tunnels are dug to a sufficient depth in the right kind of
rock--a thousand or more feet into the earth--they are extraordinarily
difficult to breach. Even a medium-yield nuclear weapon detonated above ground
may not be powerful enough to do the job. Reportedly acting with help from North
Korea (and as Emanuele Ottolenghi notes in
the July-August Commentary, employing imported European machinery), Iran
has built dozens of underground bunkers to house its missile and nuclear
programs.

The United States
(and presumably Israel)
is urgently developing ways to neutralize such targets. Concepts range the
gamut from munitions that deliver a powerful shock into the adjoining bedrock
to nonlethal methods for introducing a foul odor into the underground chambers,
rendering human habitation unbearable.

The problems posed by tunneling seldom come in for public discussion. This
happened most recently in 2005 when Congress shelved a Bush administration plan
merely to study development of something called the Robust Nuclear Earth
Penetrator (RNEP), amid talk it would ignite an arms race. RNEP was a weapon
that would have served as a deterrent to any regime thinking it could buy
invulnerability by digging deep. Its defeat was ironic because only a few years
earlier, without a peep from Congress, the Clinton
administration pushed through the innocuously named B61-11 bomb, which had
strikingly similar characteristics, though it tends to break apart when boring
into certain types of geological formations in which a hardened target might be
located.

Whatever the fate of the RNEP, nuclear weapons were never the best answer to
the tunneling problem given the prohibitive political costs of ever employing
them. More practical would be the Massive Ordnance Penetrator, a 30,000-pound
package under development jointly by Boeing and Northrop Grumman that is the
largest conventional bomb ever built. Precision guided like everything else
these days, it would be the ideal weapon to rattle--and perhaps pulverize--a
target like Iran's
underground uranium-enrichment facility at Natanz.

In one of his recent outbursts, Iran's
president, Mahmoud Ahmadinejad, called Israel
a "stinking corpse," destined to disappear. Such outrageous language
coming--not for the first time--from the head of a state seeking nuclear
weapons, has made the Iranian nuclear program all the more ominous. The day is
clearly growing closer when the West is going to either face the challenge or,
if it permits the ayatollahs to acquire nuclear weapons, suffer a strategic
setback with a range of predictable and unpredictable consequences. The Massive
Ordnance Penetrator, still in the testing phase, cannot be fitted to the bays
of American bombers a day too soon.

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